EPA tightens ground-level ozone standard to 70 ppb
Green Car Congress
OCTOBER 1, 2015
The US Environmental Protection Agency (EPA). issued its final rule revising the National Ambient Air Quality Standards (NAAQS) for ground-level ozone to 70 parts per billion (ppb) from 75 ppb to protect public health. Ground-level ozone forms when nitrogen oxides (NO x ) and volatile organic compounds (VOCs) react in the air.
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